This is the Relative Name (RN) of a reference to a child managed-object class that a policy definition applies to, the single naming component that distinguishes this ChildClass instance from its sibling instances under the same parent object. UCS Manager appends this RN to the parent's DN to build the full path, so it is the piece an admin checks when several ChildClass instances exist side by side and need to be told apart, because it tells UCS Manager which subordinate class a given policy's settings should propagate down to. For a policy definition that needs to know which child object type it governs, if two ChildClass instances share the same parent, this RN is the one field that tells an admin which of the two a given SNMP row is actually describing.